Valerie Harper went public with her terminal brain cancer diagnosis in March 2013, but five months later, things are looking hopeful for the beloved Mary Tyler Moore star.

In fact, according to her doctor, the 74-year-old actress is "getting pretty close to remission." But, as Dr. Jeremy Rudnick explained in an interview excerpted on Today, Thursday, Aug. 29, the rare form of cancer will still be fatal.

"It defies the odds," he explained of Valerie's response to chemotherapy as well as alternative treatments like acupuncture, but he explained that her leptomeningeal carcinomatosis will "develop resistance to the therapy." Meaning? "It's not a matter of if (the cancer becomes resistant)," said Dr. Rudnick, "it's a matter of when."